MADRID (AP) — The doctor at the heart of cycling's Operation Puerto doping scandal is going to jail, but the key evidence that could implicate more athletes are set to be destroyed — preventing sport agencies from trying to uncover who else may have been cheating.

Spanish doctor Eufemiano Fuentes was found guilty Tuesday of endangering public health and given a one-year suspended jail sentence in the Operation Puerto case. Fuentes was also barred from medical practice in sports for four years and ordered to pay a fine 4,650 euros ($6,000).

But in a decision that drew criticism from some anti-doping officials, Judge Julia Santamaria also said that the more than 100 blood bags that were seized seven years ago when police raided Fuentes' Madrid clinics should be destroyed. That would rule out any possible investigations by the World Anti-Doping Agency and Spain's national anti-doping body, who have said they want to examine the bags to identify all the athletes involved. Santamaria said Spain's privacy laws prevented the bags from being made available.

Several prominent cyclists have been identified in the scandal, but Fuentes testified that he also treated athletes from other sports — without giving their names.

Ana Munoz, of Spain's anti-doping agency said she would appeal the decision to destroy the bags, arguing they contained vital evidence which can still be used.

"For the Spanish Anti-Doping Agency it is very important to know the whole truth and, with this sentence, we only know a part of the truth," Munoz said. "We know the truth that says that Dr. Fuentes is not a good doctor because he did some practices that are very bad for the health of athletes. But, on the other hand, it is necessary to know the names of the athletes".

The bags contained red blood cells and plasma that had been separated by Fuentes from his patients through the use of sophisticated centrifuges.

According to the judge, Fuentes' practices were aimed purely at improving athletes' performances, but they also posed a threat to their health.

The judge said Fuentes timed blood extractions and transfusions with athletes' race calendars, with the aim of improving their results and evading detection in doping controls.

Former professional rider Jesus Manzano, who was a plaintiff in the case and had sought compensation from Fuentes and others for allegedly endangering his life, said the verdict was far too lenient.

"For this kind of verdict you don't even need to study to become a judge," he said. "They've just made me waste another day of work."

Manzano had given testimony detailing a range of doping techniques used to boost performance, telling Santamaria in February that two of the drugs he was given were developed for use in animals.

"Actovegin and Oxiglobin are for animals," Manzano said. "We used to joke in the team that some days you barked and others you mooed."

The court also sentenced former cycling team official Ignacio Labarta to four months in jail. It acquitted the other three people on trial: Yolanda Fuentes, Manuel Saiz and Vicente Belda.

Defendants who receive sentences of less than two years in Spain generally do not go to jail unless they have previous convictions.

Fuentes has 10 days to appeal.

WADA and Ana Munoz, head of Spain's new anti-doping agency, had requested access to the evidence contained in the blood bags for possible testing using the latest scientific techniques.

Although the bags will not be destroyed until appeals are heard, their eventual destruction puts an end to any further cases that could have been instigated by WADA or Munoz.

Operation Puerto implicated more than 50 cyclists, only a few of whom have been sanctioned for cheating. The case raised suspicions that the bags could have contained evidence linking other top athletes who used Fuentes' services.

Fuentes testified during the trial that he had clients from other sports, including football, tennis, boxing and athletics, but they were not identified.

No cyclists were on trial because doping was not an offense in 2006 when police raided Fuentes' clinics and laboratories. Spain has since passed anti-doping legislation, with an even stricter anti-doping bill to be voted on by parliament this summer.

Madrid is bidding for the 2020 Olympics and Munoz has said she is determined to pursue a much harder line on sports cheats.